Effects of sugar additives on protein stability of recombinant human serum albumin during lyophilization and storage

Few researches on the protein stabilization of recombinant human serum albumin (rHSA) have been done. In the present study, we assessed the impact of sugar lyoprotectants on the protein stability of lyophilized rHSA (65 KDa) in the solid state. For the assessment, rHSA was formulated with sucrose and trehalose, respectively, alone or in combination with mannitol, which were lyophilized and stored at 35 degrees C. Degradation and aggregation of the resulting lyophilized formulations was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Induction of amorphous state by the lyophilactants with rHSA was determined by differential scanning calorimetry (DSC). The protein secondary structure of the rHSA in the formulations was analyzed by Fourier transform infrared spectroscopy (FT-IR). Results from SDS-PAGE analysis displayed that mannitol formulation caused aggregation resulting in a few bands that were greater than 65 KDa, whereas sucrose and trehalose formulations revealed no such aggregation. However, the aggregation of the protein decreased when mannitol was combined with sucrose or trehalose. DSC measurement supported the electrophoresis data showing that sucrose and trehalose formed complete amorphous state, but mannitol induced a partial amorphous state. These data indicate during lyophilization the most effective protein protection against aggregation was provided by sucrose and trehalose. The protection lasted during 4 months storage at 35 degrees C. FT-IR analysis displayed that the sucrose formulation inhibited deamidation. In conclusion, our data suggest that sucrose and trehalose as additives seems to be sufficient to protect from lyophilization of rHSA protein and also maintain its stability in the solid state during storage.     

Recurrent type B intramural hematoma progressed into type A acute aortic dissection in a young otherwise healthy woman: are there unknown background factors?

Intramural hematoma is reported with increasing frequency but the recurrence after complete resolution is rarely reported. We herewith describe a case of type B intramural hematoma in an otherwise healthy 39-year-old woman showing unusual clinical course in which acute aortic dissection developed three months after complete resolution of intramural hematoma. The case clearly reminded us of the potential of intramural hematoma for recurrence and progression to frank aortic dissection even after complete resolution.     

Routine preprocedural transesophageal echocardiography might not be necessary for stroke prevention evaluation in AF patients on anticoagulation therapy

Background

Preprocedural transesophageal echocardiography (TEE) is used to reduce the stroke during atrial fibrillation (AF) ablation. This study evaluated whether routine preprocedural TEE in addition to multidetector computed tomography (MDCT) is necessary to prevent periprocedural stroke in AF ablation.

Methods

Each patient underwent MDCT and TEE (group 1, n = 247) or MDCT alone (group 2, n = 103) for the initial evaluation before AF ablation. In group 2, TEE was performed only in patients who had left atrial (LA) thrombus or blood stasis in MDCT.

Results

There was no difference in sex, CHADS₂ score, or LA dimension between the two groups. In group 1, a thrombus was detected in 12 (5%) and 6 (2%) patients by the MDCT and TEE, respectively. All (100%) patients, who were revealed to have thrombus in TEE, also had a thrombus in MDCT. In group 2, 3 (3%) patients exhibited LA thrombus in MDCT, among whom thrombus was observed in only one patient (1%) in TEE. AF ablation was not performed in patients with thrombus. While one patient had a periprocedural stroke in group 1, no patient had in group 2 (P = 0.52).

Conclusion

The overall periprocedural stroke rate was low (0.3%) in AF patients on anticoagulation therapy. The preprocedural MDCT detected all patients with the LA thrombus. In AF patients with low CHADS2 score, optimal anticoagulation and relatively preserved left ventricular ejection fraction, routine preprocedural TEE in addition to the MDCT might not be necessary to decrease the periprocedural stroke rate.     

Prediabetes Is Associated with a High-Risk Colorectal Adenoma

Background

Type 2 diabetes mellitus is associated with an increased risk of colorectal neoplasia. However, association between prediabetes and colorectal adenoma has not been reported.

Aims

The aim of this study was to evaluate the relationship between prediabetes and the presence of colorectal adenomas.

Methods

Consecutive prediabetic subjects who underwent screening colonoscopy were enrolled at Kyung Hee University Hospital in Gangdong, Seoul, Korea, between June 2006 and May 2012. Non-prediabetic subjects were separately pooled from the database of the Center for Health Promotion between January 2012 and May 2012. Prediabetes was defined according to the recommendations of the American Diabetes Association. The prevalence of colorectal adenomas and their characteristics were compared between prediabetic and non-prediabetic groups.

Results

The prevalence of colorectal adenoma was higher in prediabetic subjects than in non-prediabetic subjects (39.6 vs. 30.6 %, respectively, p = 0.019). Prediabetic subjects had more multiple and high-risk adenomas than the control group in non-matched analysis (p = 0.000, respectively). In age-matched analysis, the prevalence of multiple and high-risk adenomas were significantly higher in a prediabetic group than those in a control group (44.4 vs. 28.4 %, p = 0.034; 51.9 vs. 34.6 %, p = 0.026, respectively). Furthermore, prediabetes (odds ratio = 2.198; 95 % confidence interval = 1.042–4.637; p = 0.039) was found to be an independent risk factor for a high-risk adenoma by multivariate analysis.

Conclusions

The prevalence of multiple and high-risk colorectal adenomas is significantly higher in the prediabetic subjects than those in the control group. Furthermore, prediabetes was found to be an independent risk factor for a high-risk colorectal adenoma.     

Critical role of the JNK-p53-GADD45α apoptotic cascade in mediating oxidative cytotoxicity in hippocampal neurons

BACKGROUND AND PURPOSE

Glutamate-induced oxidative stress plays a critical role in the induction of neuronal cell death in a number of disease states. We sought to determine the role of the c-Jun NH₂-terminal kinase (JNK)-p53-growth arrest and DNA damage-inducible gene (GADD) 45α apoptotic cascade in mediating glutamate-induced oxidative cytotoxicity in hippocampal neuronal cells.

EXPERIMENTAL APPROACH

HT22 cells, a mouse hippocampal neuronal cell line, were treated with glutamate to induce oxidative stress in vitro. Kainic acid-induced oxidative damage to the hippocampus in rats was used as an in vivo model. The signalling molecules along the JNK-p53-GADD45α cascade were probed with various means to determine their contributions to oxidative neurotoxicity.

KEY RESULTS

Treatment of HT22 cells with glutamate increased the mRNA and protein levels of GADD45α, and these increases were suppressed by p53 knock-down. Knock-down of either p53 or GADD45α also prevented glutamate-induced cell death. Glutamate-induced p53 activation was preceded by accumulation of reactive oxygen species, and co-treatment with N-acetyl-cysteine prevented glutamate-induced p53 activation and GADD45α expression. Knock-down of MKK4 or JNK, or the presence of SP600125 (a JNK inhibitor), each inhibited glutamate-induced p53 activation and GADD45α expression. In addition, we also confirmed the involvement of GADD45α in mediating kainic acid-induced hippocampal oxidative neurotoxicity in vivo.

CONCLUSIONS AND IMPLICATIONS

Activation of the JNK-p53-GADD45α cascade played a critical role in mediating oxidative cytotoxicity in hippocampal neurons. Pharmacological inhibition of this signalling cascade may provide an effective strategy for neuroprotection.     

Honokiol attenuates vascular contraction through the inhibition of the RhoA/Rho-kinase signalling pathway in rat aortic rings

Objectives Honokiol is a small‐molecule polyphenol isolated from the species Magnolia obovata. We hypothesized that honokiol attenuated vascular contractions through the inhibition of the RhoA/Rho‐kinase signalling pathway. Methods Rat aortic rings were denuded of endothelium, mounted in organ baths, and subjected to contraction or relaxation. Phosphorylation of 20 kDa myosin light chains (MLC₂₀), myosin phosphatase targeting subunit 1 (MYPT1) and protein kinase C (PKC)‐potentiated inhibitory protein for heterotrimeric myosin light chain phosphatase (MLCP) of 17 kDa (CPI17) were examined by immunoblot. We also measured the amount of guanosine triphosphate RhoA as a marker for RhoA activation. Key findings Pretreatment with honokiol dose‐dependently inhibited the concentration–response curves in response to sodium fluoride (NaF) or thromboxane A₂ agonist U46619. Honokiol decreased the phosphorylation levels of MLC₂₀, MYPT1_Thr855 and CPI17_Thr38 as well as the activation of RhoA induced by 8.0 mm NaF or 30 nm U46619. Conclusions These results demonstrated that honokiol attenuated vascular contraction through the inhibition of the RhoA/Rho‐kinase signalling pathway.     

The Influence of Dietary Patterns on the Nutritional Profile in a Korean Child Cohort Study

Objectives

The aim of the present study was to identify the major dietary patterns of seven- and eight-year-old Korean children and to examine the relationship between dietary patterns and obesity, nutrient intake, and diet quality.

Methods

The subjects were 284 seven- and eight-year-old children who participated in the Gwacheon child cohort study. Three dietary patterns emerged from the factor analysis: Korean, modified Western, and Western. Cluster analysis was used to classify the subjects into two dietary groups: Korean and Western diet patterns.

Results

The two different dietary patterns were closely related to dietary quality which in turn was related to health risks. The Western diet group had a lower fiber intake, a higher intake of energy, fat and calcium and a higher dietary diversity score (DDS) than the Korean diet group. The number of days when fruit, milk and dairy products were omitted from the diet was higher for the Korean diet group than for the Western group.

Conclusions

Dietary patterns and related diet quality should be considered when designing nutrition policy and intervention programs for children.     

Willingness to accept H1N1 pandemic influenza vaccine: A cross-sectional study of Hong Kong community nurses

Background  

The 2009 pandemic of influenza A (H1N1) infection has alerted many governments to make preparedness plan to control the spread of influenza A (H1N1) infection. Vaccination for influenza is one of the most important primary preventative measures to reduce the disease burden. Our study aims to assess the willingness of nurses who work for the community nursing service (CNS) in Hong Kong on their acceptance of influenza A (H1N1) influenza vaccination.     

Development of a dish-based, semi-quantitative FFQ for the Korean diet and cancer research using a database approach

We used a database approach in developing a dish-based, semi-quantitative FFQ for Korean diet and cancer research. Cancer-related dietary factors (CRDF) recognised in the scientific community and dietary intake data from the 2001 Korean National Health and Nutrition Examination Survey and the 2002 Korean National Nutrition Survey by Season were used. The list of dishes (n 993) was those reported to be consumed by individuals over 30 years of age during all four seasons. The resulting 112-dish list was selected using contribution analyses and variability analyses to detect between-person variation for CRDF and non-CRDF nutrients. Variations of each dish were grouped into one dish for the final list of 112 dishes, which were then linked to the nutrient database. The final 112 dish items consisted of nine Korean staple dishes, including rice and noodles, twenty-five soups and stews, fifty-four side dishes, nine beverages, nine fruit dishes and six alcoholic beverages. The percentage coverages of energy, protein, fat, carbohydrate and alcohol intake in the selected 112 dishes were 82·4, 76·4, 68·9, 86·0 and 99·8?%, respectively. Dietary exposure to cancer-related Korean dietary factors can be assessed by this new dish-based, semi-quantitative FFQ. This new instrument can calculate the intake of CRDF along with non-CRDF nutrient intake for cancer research.